In order to study the physical properties of the quasar HE0359-3959, we built a grid of photoionization simulations using the CLOUDY code [1]}, [2]}. For our simulations we considerer a Mattews and Ferland continuum [3]}, a plane-parallel geometry, a metallicity 5Z\(\odot \)  with an overabundance of Al and Si with respect to carbon (by a factor of three), and a column density of N\({\rm _c}\) =10\(^{23}\)  cm\(^{-2}\) . See [4]} for more details. Our simulations span the density range 7.00\(\le \) log(n\(\mathrm {_H}\) )\(\le \) 14.00 and –4.5\(\le \) log(\(U\) )\(\le \) 0.00 for the ionization parameter, in intervals of 0.25 dex. More details about the cloudy simulations can be found in [5]}. Using the UV lines, we define three groups of diagnostic ratios::
